Electrical regulator.



A A. TIRRILL.

ELECTRICAL REGULATOR,-

APPLICATlON FILED JAN-'5, 1 915.

1,216,51 8. Patented Feb. 20, 1917.

WITNESSES INVENTOR AMP/7 A. 7/'/*/"///.

ATTORNEY L, I" LEITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELLllBTREG rlglii ELANUFAJTURING COMYANY, CORPORATION OF PENNSYLVANIA.

ELECTRICAL REGULATOR.

Application filed January 5, 1915.

T aZZwFwm may concern:

lie it known that l, ALLEN A. Tnnnrm, a citizen of the United States,and a resident of Pittsburgh, in the county of Allegheny and State ol.Pennsylvania, have invented a new and useful Improvement in ElectricalKeg-gala tors, of which the following is a specification.

My invention relates to electrical regulators and particularly to thosein which the regulation is el'lected by opening and closing a shuntcircuit to a resistance in series with the field magnet winding of anexcitcr or other dynamo-clectric machine.

'llhe object of my invention is to provide a regulator ol the characterindicated that shall. be ell'ective aiulreiiablc in operation, andcapable ol? maintaining; the voltage or other electrical quantity of acircuit; substan tially onstant in value and of promptly and accuratelyrestoring); it to its normal value tollmving a change of load upon, orother disturbance o'l, a, system. i

The present invention is an improvement over that set 'lorth in myapplication, Serial No. 822,125-"l, iled Mar. 3, 191 1 the improvementconsisting in the provision of mechanical means for assisting inpreventing huntinn; and in musing the regulator to be more romptlytrestored to a condition of stability or equilibriiun.

lily invention is illustrated in the accompanying drawing, Figure 1 ol vwhich is a side view ol the main controlling clement ol the regulator,the circuit connections beihg illustrated diagrammalically. Fig. 2 is anend view oi the main controlling element of the regulator, and Fig, 3 isa side and sectional view oi some of the parts of the regulator.

A system in connection with which the regulator may be convenientlyemployed com 'irises a enerator 1 that supplies current to a suitabledistributing circuit 2 fil -land the field magnet winding 5 of which issu iplied lrom exciter bus bars (37. An ixcitcr 8 that is connected tothe bus bars t37 is provided with a field magnet windinc: 9 in serieswith which is a suitable variable resistor 10, the eti'ective value ofwhich is determined hy opening; and closing a shunt circuit thereto bymeans of a. relay 11 having cooperating; stationary and movable membersand 1.3, respectively, that are $pecification of Letters Patent.

Patented Feb. 20, 1917.

Serial No. 565.

connected to the terminals of the resistor 10. The relay 11 is providedwith an energizing winding ll: that is connectedin parallel with anenergizingwinding of a similar relay 16, both of said windings beingsupplied with current from the excite]- or from any other suitablesource.

The circuit ol the windings 14 and 15 is controlled by a pair ofcooperating contact terminals 17 and 18, the former of which is mountedupon a plate spring ll) intermediate its ends. ()ne end of the spring 19is clamped in a stationary post 20, and the other end extends betweentwo screws 21 and 22, serving as adjustable means for limiting themovements of the contact terminal The contact terminal 18 is mountedupon the upper face of the lower cross-piece.

ol a small yoke 23 that is carried by the core member 2-l o'l anelectro-magnct having an energizing winding25. The upper end.

The moven'ients ol the solenoid core 24 and of the contact member 18 areretarded by means of a dash pot that is secured to the lower end of theframe 29, and their movements are also limited by reason of theengagement ol :1 boss or projection 31, that is provided upon the lowerface of the upper crosspicce ol thc'yolic 23, with the upper face of theplate spring 19 that carries the. contact terminal 17. The coil 25receives current from the dist ributing circuit 2-34-, though it mayreceive current from any other suitable source, and its circuit iscontrolled by cooperating stationary and movable contact terminals 33and 34, respectively, of the relay 16.

Upon the upper end of the core member 24 is a laterally extending cap orend piece '21-, and, secured to one side of the frame 29 adjacent to thesaid end piece is a magnetizable plate 29 thatis adjustable verticallyof the lrame to vary its effect upon the core member. When the coil 25is energized, the core 24 is attracted slightly toward the plate, andthe contact terminals 17 and 18 are Ettbrouq'ht together with a rubbingaction, thereby insuring good electrical contact between them andkeeping them clean.

The frame 29 is suspended from a lever 35 that is fulcrumed in astationary bracket 36, the said lever and frame being operativelyconnected by means of a universal joint comprising a yoke 37 that ispivotally connected both to the lever 35 and to the upper end of theframe 29, the pivotal axes inter secting each other at substantiallyright an gles. The object of employing a universal oint is to permit offree suspension ot'the frame 29 and the parts carried thereby, in orderthat binding of joints, and consequent friction and inaccuracy ofoperation, may be avoided.

Theend of the lever opposite to that to which the frame 29 is connectedcarries an adjustable counterweight 31), that is resiliently suspendedtherefrom, and the core member 4-0 of an electromagnet having anenergizing winding 41, the core member be ing guided in its movementsand prevented from swinging by means of a guide 42. The coil 41 receivescurrent proportional to the voltage of the distributing circuit 2' '3fh,and, accordingly, varies thepositions of the lever and of the frame 29in accordance with the said voltage. However, ifdesired, the coil ellmay be caused to vary the positions of said parts in accordance with anyother desiied electrical condition. In thus varying the position of theframe 29, the position of the contact terminal 18 with respectto theterminal 17 is likewise varied,

so that the initial distance between the said contact terminals, thatis, the distance which would exist between them, it the winding 25 werenot energized, is varied in accordance with the voltage or otherselected electrical. condition of the distributing circuit.

The core member 40 for the solenoid 41 is sus1.)en -led from the lever35 by means of a non-magnetizable rod 43 having an aperture in its upperend to receive a pivot pin 44 that is provided with a washer or shoulder45 located somewhat nearer one end than the other. the pivotalconnection between the'said lever and the rod 43, is a bracket 46 thatis apertured to receive the pivot pin 44. During normal operation of theregulator, the pivot pin itoccupies the position shown, but in order tofacilitate adjustment of the regulator prior to placing it in operation,the pivot pin 4' is withdrawn and its longer end inserted through thelever and into the aperture in the bracket 46. The position of the lever35 is thereby fixed and the adjustment of the spring 26, of the stops 21and 22, and of the other part. of the regulator carried effected.

The lever 35 is engaged upon opposite by the frame 29,;may be readilyBehind the lever 35 adjacent to sides by the ends of two levers-47 and48 that are pivoted in the bracket 36, preferably re'-' spectively aboveand below the pivot of the lever 35. The said levers'are connected by ahelical tension spring- 49, the tension of which may be regulated by anadjusting screw 50, but they may be connected by any other suitableresilient means. Extending through of adjacent to the levers -17 and 48is a ro'dor stem. 51 that is connected to the piston or movable memberof a dash pot 52, and that is threaded at its upper end for thereception of nuts 53 and 54 that serve as shoulders for engagement withthe levers 47 and 48 whereby the levers may actuate the movable memberof the dash pot. The movable member of the dashpot is. by this means,resiliently connected to the lever 35 and only indirectly retards themovements of the lever. The lever 35 is thus permitted to move somewhatindependently, and in advance, of the dash pot piston, and, accordingly,it can respond more promptly to changes in voltage than it otherwisecould, while, at the same time, the dash pot serves to prevent extremefluctuations and hunting.

A suitable spring 55, the tension of which may be regulated, may also beemployed, if desired, for effecting fine adjustment of the voltage valuewhich the regulator tends to maintain.

. If, in the operation of the regulator, the load upon the circuit 23-4increases to such an amount as to cause the voltage of the 'circuit todecrease, the coil 41 will be energized to a somewhat less degree, andthe frame 29 will consequently be raised slightly, with the result thatthe contact terminal 18 will he brought closer to, or into engagementwith, the terminal 17. Upon engagement of the said contact terminals,the circuit of the relay windings 14 and 15 is established, and thecontact terminals of the relays are caused to engage. Engagement of thecontact terminals 12 and 13 establishes a shunt to the resistor 10, andthe voltages of the eX- citer and generator are correspondinglyincreased to compensate for the decreased voltage resulting from theincrease of load. Engagement of the contact terminals and iltestablishesthe circuit of the coil 25, which thereupon attracts its core 24 andcauses sep aration of the contact terminals 17 and 18. Upon theinterruption of the circuit of the coils l-t and 15, which is thuseffected, the contact terminals of the relays disengage and the shuntcircuit is again established to the resistor 10, while the circuit ofthe coil 25 is again interrupted.

The coil 25 is thus alternately energized and deenergized and serves tovibrate the contact terminals 17 and 18 into and out of engagement,while the coil 41 serves to vary the position of the contact terminal P8with respect to the terminal 17 so that the said terminals will engageand disengage for varying periods dependent upon the voltage of thecircuit 2-3-4. The arrangement is such that the resistor-10 is shuntedfor a greater average period when there is a tendency for the voltage ofthe circuit 234= to be reduced, and for a shorter average period :whentendency is toward a higher voltage, with the result that the voltage ofthe distributing circuit is maintained substantially uniform. I

By reason of the fact that the movable member of the dash pct 52 isresiliently connected to the lever 35, the lever may move promptly inresponse to voltage variations. In doing so, however, it subjects thespring 49 to tension, and the spring then causes the dash pot piston tofollow the movement. The adjustment of the spring and of the dash potare such that, when the lever is moved by a voltage change caused by anincrease or decrease of load, the movable member of the dash pot willfollow only to approximately a position corresponding to the correctposition for the lever for normal voltage at that load, the leverreturning to that position due to the change of voltage caused by itsfirst movement. For instance, if the voltage increases, the left-handend'of the lever is and the exertion of an upward pull on the dash potstem 51. The dash pot retards the movement ofthe lever 35, but itspiston does not move as far as the lever, because the lever begins itsreturn or downward movement, due to the change of voltage caused by itsupward movement, before it has had time to do so.

I claim as my invention An electrical regulator comprising cooperatingcontact members, a lever for actuating one of said members, anelectromagrret for actuating the lever, members engaging oppositesidesof the lever, a resilient connection between said members,and aretarding device actuated by said members. 1 In testimony whereof, Ihave hereunto subscribed my name this 24th day of Dec., 1914.

ALLEN A. TIRRILL.

Witnesses:

' OTTO S. SCHAIRER,

B. B. HINES.

